Improved process of hardemjwg steel



Toallwhom'itma/yconcem:

Be it'known that I,- HENRY BROOKE, of Pittsburg, in the county ofAllegheny, and State ofPennsylvauia,

HENRYABRDO-KE. or; Prr'rsBnRc, PENNSYLVANIA.

' Letters Patent No. 90,075, dated Ma 13,1869.

" .mrnovnn PROCESS or meme- 3mm,

T e Schedule referred to'in these Letters Patent-and making part of thesame.

have invented certain new and useful Improvements in l r Hardening SteelandI do hereby declare that the following is a' full, clear, and exactdescription thereof.

The nature of my invention consists in a process of making and hardeningwhat is known as semisteel,

or homogeneous castings, and is adapted to the following articlesofmanufacture, viz, rollers of all descrip tions; shear-blades, circular.and other; cutters, machineknives, cannon-shot, plow-mould boards, andengravers plates. v i

To enable others skilled in the art to use my invention, I will"describe the process, first, as adapted to linear articles, suchas plowmould-boards or engravcrs plates.

Ordinary bar-iron is cut to any suitable length, and

. deposited, with the ordinary fluxes, in an ordinary melting-pot, orcrucible, and is subjected to the heat arising from any ordinarymelting,or air-furnace.

When the metal acquires a fluid state, an ordinary iron mould isprovided, of the size and shape requisite for the required casting. Aplate of ordinary iron, and

of the shape of the back ofthe required casting, is

- placed in the mould, in scuba manner, that when the molten metal ispoured into the mpuld, it will flow up 1 against said metalplate, towhich it-lvill adhere;

When the casting becomes cold,:it is taken from the mould, and its outersurfaces made true and free from imperfections, by theaid of anysuitable machinery.

It is thenftaken and deposited in an ordinary carbonizing,or.,c0nverting-furnace, where it'is subjected to the heat thereof. i

. Having remained in'the furnace snificient time, said i 1 periodof timebeing regulated by the degree of hardness the casting is calculated to.have, it is taken out,

p and the iron plate removed from the same, and all its? surfaces willbe carbonized, and will have the degree of hardness cast-steelpossesses, save the surface which. was against the iron plate,whichfiiotbein'g subjected to the carbonizing-process, in consequence ofthe iron plate intervening, possesses the nature and tensile strengthofi ordinary wrought-iron. V 1

1 In casting and hardening cylindrical articles, such as rollers, themethod employed of meltingbar-iron is the same as before described.Moulds are furnished, of octagonal or hexagonal shape, and the fluidmetal poured therein. g

Whensolidified,'the casting is'taken to an ordinary steam-hammer, bywhose aid it is made as nearly cylindiical as possible. It is then takento the'ordinary carbonizing, or converting-furnace, and carbonized towhatever degree of hardness is required, leavin'g'the inner portion ofthe same wrought-iron, whilst the outer surface has become steel.

The advantages arising from the use of my invention are, thatsemi-steel, or homogeneous castings, when hardened, possess greatervirtues than cast-steel does,

since steel is very liable to fracture by any sudden jar, ordisarrangement of machinery, especially when it is very hard.

Rbllers, when constructed wholly of steel, are made of greater diameter,in consequence of this fact, than if they were made of WIOHghlrlI'OH;but, as the outer surfaces of wrought-iron rollers are not of suflicienthard ness to withstand the pressure of the metals passmg through them,they areinadmissible.

Rollers made by my process, as herein described,

possessjtwo natures and qualities, viz, that of wroughtiron in the mainbody, and'steel at their peripheries,

being, as it were,.steel rollers with wrought-iron cores. Such rollerscan be made of smaller diameter, not only saving metal, but also drawingout the required metal more uniformly than rollers of larger diameters.

As shear-blades have been heretofore constructed, they have been made ofwrought-iron, with a steelpiece welded thereto, requiring considerableskilled labor to perform the same, and the blades are also liable toaccident, as the weld is oftentimes defective. By the use of mydescribed process,-such articles are .made solid, but are hard at therequired point.

Cannon-shot, when constructed in like manner, will withstand aheavier'concussion. The point, being carbonized, will penetrate, whilstthe base, being homog'eneous, will not sufier molecular deterioration.

Having thus described the nature and use of my invention,

What I claim as new, and desire to secure by Letters Patent, is-- Theprocess of making and hardening homogeneous castings, substantially asherein described,.when applied tothe articles enumerated herein. 7

In testimony that I claim the foregoing as mytg wn, I affix mysignature, in presence of two witnesses.

T p 7 HENRY BROOKE.

rWitnesses: I

. PERGEVAL Bncunrr,

B. M. Onneo.

